Data cards are commonly constructed with a molded plastic body of moderate width and length such as 5.3 cm by 8.5 cm, but small thickness such as 5 mm. A circuit board assembly that is installed on the body, includes one or more integrated circuits that usually store data but may include only processing circuitry. Metallic top and bottom covers complete the card. Such data cards are especially useful in electronic equipment or devices of small thickness, such as lap top computers that may have a thickness of much less than one inch. Standard JEIDA cards have a thickness of five millimeters, which enables them to be inserted into thin slots of the electronic device.
While the top and bottom metallic covers provide good EMI (electromagnetic interference) shielding, there still can be considerable leakage through the perimeter of the card. A perimeter EMI shielding which added a minimal amount to the size of the card, and which was readily installable so it securely held to the molded body and was connected to the ground plane of the circuit board, and which preferably also helped to ground the covers, would be of value.